<!DOCTYPE html>
<html>

<head>
    <meta charset='utf-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <title>Page Title</title>
    <meta name='viewport' content='width=device-width, initial-scale=1'>
    <!-- <link rel='stylesheet' type='text/css' media='screen' href='main.css'>
    <script src='main.js'></script> -->

    <style>
        .box {
            width: 800px;
            height: 800px;
        }

        .inner {
            width: 100px;
            height: 100px;
        }
    </style>
</head>

<body>

    <div class="box">
        <div class="inner"></div>
    </div>

    <script>

    </script>
</body>

</html>